A control system and a control method for determining a likelihood of a lane change by a vehicle traveling in front of a host vehicle is disclosed. This control system and control method are based in particular on a surroundings sensor system in the host motor vehicle, and assist a driver or an autonomously driving motor vehicle. For semiautonomous motor vehicles and autonomously controlled motor vehicles, the control system and a control method increase the safety and the driving comfort of the occupants of the motor vehicle.